JPH04190060A - Expansion valve for air-conditioner - Google Patents

Abstract

PURPOSE:To make unnecessary an outdoor unit check valve provided in parallel with an expansion valve, and to prevent a refrigerant from leaking, by a method wherein in a valve seat part for the expansion valve, a bypass part communicating with both sides of an outdoor unit and an indoor unit is formed and a check valve opened in the time of cooling-operation and closed in the time of heating-operation is provided. CONSTITUTION:A check valve 20 is provided in a valve seat 4 for an expansion valve 1. In the time of heating-operation, a refrigerant flows into a valve case 2 through a part 3a on the side of an indoor unit and passes the check valve 20, and the flow thereof is regulated by both a valve member 6 and a valve seat port 19. Then the refrigerant flows to the side of a port 3b on the side of an outdoor unit and the flow thereof is controlled by a temperature-sensing tube 9. At this time, since a bypass part 18 on a fixed seat 17 is depressed on the side of the seat 17 by a coil spring 14, it is closed. In the time of cooling-operation, the refrigerant flows through the port 3n on the side of the outdoor unit, and the flow pressure thereof lifts a seat 16 on the bypass part 18. After that, the refrigerant passes a communicating port 15 on the seat 16, flows in a valve chamber 4a, and flows to the side of the port 3a. Therefore, a check valve provided in parallel with an expansion valve conventionally provided is unnecessary.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Field of Application) The present invention relates to an expansion valve for an air conditioner that adjusts the flow rate of a refrigerant, and particularly relates to an expansion valve for an air conditioner that adjusts the flow rate of a refrigerant. This relates to the expansion valve of a harmonizer.

(Prior Art) FIG. 6 is an explanatory diagram showing a refrigeration cycle of a conventional heat pump type air conditioner. As shown in the figure, this heat pump type air conditioner includes an outdoor unit C that is placed outdoors and houses an outdoor heat exchanger a, an expansion valve, etc. inside, an indoor heat exchanger d that is placed indoors, and an indoor heat exchanger d that is placed indoors. The refrigeration cycle is separated into an indoor unit f containing a compressor e, etc., and connected by a refrigerant pipe g that transfers refrigerant between the outdoor unit C and the indoor unit f.

Furthermore, this heat pump type air conditioner is equipped with a four-way valve, which performs cooling and heating by switching the flow direction of the refrigerant.

To explain this simply, during heating operation, the refrigerant is sent from the liquid tank i through the refrigerant pipe g to the outdoor unit C, as shown by the dotted line arrow in the figure, and the pressure drops as it passes through the expansion valve. After being sent to outdoor heat exchanger a, it absorbs outdoor heat and becomes gas. The refrigerant that has become a gas is sent from the outdoor heat exchanger a to the indoor unit f via the refrigerant pipe g,
It is sucked into a compressor e through a four-way valve h and an accumulator j, and is compressed. The refrigerant, which has become high temperature and high pressure due to the pressure Nae, is sent again to the four-way valve via the muffler k, enters the indoor heat exchanger d, releases heat indoors, becomes liquid, and is passed through the strainer 1, indoor check valve m, It passes through the dryer n and is sent to the liquid tank i again. Furthermore, by switching the four-way valve j, the refrigerant during the cooling operation flows in the opposite direction to that during the heating operation, as shown by the solid arrow in the figure.

By the way, the expansion valve that controls the flow rate of refrigerant during heating operation is a port ol connecting the indoor unit ff1ll and the outdoor unit C side, as shown in FIG.

A valve seat 9 is formed in a valve box P formed with a valve body P, and a valve body r for opening and closing the valve seat q by IFM is provided. Therefore, the refrigerant flowing through it is directed to port 0 on the indoor unit f side, as shown by the dotted line arrow in the figure. It enters the valve box p, passes through the valve seat q, and after being controlled in flow rate by the ball-shaped valve body r seated on the valve seat q, it flows through the port o2 on the outdoor unit C side. In addition, the opening degree of the valve body r is the valve body P
The diaphragm S is controlled by a temperature-sensitive tube U connected through a capillary tube T.

(Problem to be Solved by the Invention) By the way, as mentioned above, this expansion valve obstructs the flow of refrigerant when switching from heating operation to cooling operation and refrigerant flows in the opposite direction. . Therefore, as shown in the circle in FIG. 6, an outdoor check valve (2) is provided in parallel with the expansion valve. As is well known, this outdoor check valve V is for controlling the flow of refrigerant in one direction, and functions to regulate the flow of refrigerant during heating operation and to bypass the flow of refrigerant during cooling operation. Therefore, during cooling operation, the refrigerant flows through this outdoor check valve V.

However, since this outdoor check valve V is attached to the refrigerant piping by welding, it is difficult to install and there is a risk that the refrigerant may leak from this welded portion.

Therefore, the present invention was devised to effectively solve this problem, and its purpose is to provide an air conditioner that achieves the elimination of the check valve by providing the expansion valve with a check valve function. The present invention provides an expansion valve.

Configuration of the Invention (Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention forms a valve seat in a valve box in which a port connecting the indoor unit side and the outdoor unit side is formed. In addition, in an expansion valve for an air conditioner in which the valve seat is provided with a valve body for opening and closing the same, a bypass flow path connecting the outdoor unit side and the indoor unit side is formed in the valve seat, and the bypass flow path is formed in the valve seat. The system is equipped with a check valve that opens during cooling operation and closes during heating operation.

(Function) Since the present invention is constructed as described above, the normal flow of refrigerant flowing through the expansion valve during heating operation enters the valve box from the port on the indoor unit side, and its flow rate is adjusted by the valve seat and valve body. After that, it will be discharged from the port on the outdoor unit side, but in the case of cooling operation in which the flow is in the opposite direction, it will enter the valve box from the port on the outdoor unit side and will be discharged from the valve seat installed in the valve seat. It passes through the bypass flow path of the valve and is discharged from the port on the indoor unit side. Therefore, during cooling operation, the refrigerant flows smoothly regardless of the opening degree of the valve seat and the valve body, and the flow rate is not restricted.

(Example) Next, one embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows the structure of an expansion valve for an air conditioner according to the present invention. This expansion valve 1 is for controlling the flow rate of refrigerant and adjusting the pressure of the refrigerant, and as shown in the figure, ports 3a and 3b connecting the indoor unit side and the outdoor unit side are provided in the valve box 2. It is formed. Also, this valve box 2
A substantially cylindrical valve seat 4 and a ball-shaped valve body 6 that is seated on the valve seat 4 and opens and closes the refrigerant flow path 5 are provided inside. In addition, the upper part 11 of the valve box 2
A diaphragm 7 is provided inside 2a, and a temperature sensing tube 9 is connected to this diaphragm 7 via a capillary tube 8.

Further, a connecting rod 11 is provided on the stopper 10 of the diaphragm 7 along the valve seat 4, and the piston 12 of the valve body 6 is pushed down by this connecting rod 11. Also,
A coil spring 13 is provided inside the piston 12 and urges the piston 12 upward.

Further, the temperature sensing tube 9 is attached to a refrigerant pipe, and the inside thereof is sealed with a refrigerant. The tire flam 7 is controlled via the capillary tube 8 by the volume change of the refrigerant, which changes depending on the temperature of the refrigerant pipe.

In addition, as shown in FIGS. 2 and 3, the valve seat 4
A check valve 20 is provided in the valve chamber a.

This check valve 20 is attached to a coil spring 14, a disk-shaped movable seat 16 in which a refrigerant communication hole 15 is formed in the center, and a lower opening of the valve seat 4, and a valve seat opening 19 in the center. Bypass flow N11 for causing the refrigerant to flow backward
8 consists of a plurality of disk-shaped fixed seats 17 formed around the valve seat opening 19, and normally this movable seat 1
6 is biased toward the fixed seat 17 by a coil spring 14.

Next, the present invention will be explained in detail.

As shown by the dotted arrow in FIG. 1, the flow of refrigerant during heating operation flows into the valve box 2 from the bow 3a on the indoor unit side, passes through the check valve 20 in the valve seat 4, and passes through the valve After the flow rate is adjusted by the body 6 and the valve seat port 19, it flows to the port 3b side on the outdoor unit side. The flow rate through the valve body 6 and the valve seat port 19 is controlled by the temperature sensor 9. That is, as mentioned above, the diaphragm 7 is controlled by the change in the volume of the refrigerant in the temperature sensor [9], and the connecting rod 11 connected to the diaphragm 7 moves the piston supporting the valve body 6 up and down. The opening degree of the valve body 6 and the valve seat port 19 is adjusted by the following.

To specifically explain the flow of refrigerant inside the valve seat, during heating operation, the refrigerant flows from the valve chamber 4a in the valve seat 4 to the communication hole 15 in the movable seat 16, as shown by the dotted arrow in FIG. It flows through the valve seat opening 19 of the fixed seat 17. At this time, the bypass flow path 18 of the fixed sheet 17
is blocked because the movable seat 16 is pressed against the fixed seat 17rpJ by the coil spring 14, and during heating operation, the refrigerant flows from the bypass passage 18 to the port 3.
It does not flow to the b side.

Next, during cooling operation, the refrigerant flows as shown by solid arrows in FIG. That is, the refrigerant flowing from the port 3b on the outdoor unit side flows into the bypass flow path 18 due to its flow pressure.
Push up the movable sheet 16 from the
The bypass passage 18 is opened and the opened bypass passage 1 is opened.
8, flows into the valve chamber 4a through the communication port 15 of the movable seat 16, and then flows to the port 3a side.

As described above, in the present invention, by providing the check valve 20 that controls the flow direction of the refrigerant in the valve seat 4, the refrigerant during cooling operation is regulated by the opening degree of the valve seat 4 and the valve body 6. Therefore, the fluid flows smoothly inside the expansion valve 1. Therefore, the check valve that was conventionally provided in parallel with the expansion valve becomes unnecessary.

[Effects of the Invention] As described above, according to the present invention, the outdoor check valve that was provided in parallel with the expansion valve is no longer necessary, reducing the parts cost and assembly cost, and reducing the space around the expansion valve. be able to. In addition, since there are no welded parts, there is no risk of refrigerant leaking, and there are excellent effects such as improved quality.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing an embodiment of the present invention, Fig. 2 is a perspective view showing the structure of the check valve according to the invention, and Fig. 3 is a diagram showing the flow of refrigerant in the valve seat during heating operation. Explanatory diagram, 4th
The figure is an explanatory diagram showing the flow of refrigerant in the valve seat during cooling operation, Figure 5 is an explanatory diagram showing the refrigeration cycle of a conventional air conditioner, and Figure 6 is the structure of a conventional expansion valve. FIG. In the figure, 1 is an expansion valve, 2 is a valve box, 3a, 3b are ports, 4 is a valve seat, 6 is a valve body, 18 is a bypass flow path, and 20 is a check valve.

Claims (1)

[Claims] 1. An expansion valve for an air conditioner in which a valve seat is formed in a valve box in which a port connecting an indoor unit side and an outdoor unit side is formed, and a valve body for opening and closing the valve seat is provided on the valve seat, Expansion of an air conditioner characterized in that a bypass flow path connecting an outdoor unit side and an indoor unit side is formed in the valve seat, and a check valve is provided in the bypass flow path, which opens during cooling operation and closes during heating operation. valve.